The prostaglandin synthetase microsomal enzyme system from bull seminal vesicles is being investigated by means of differential assays. The role of various effectors is being probed, as is the step in this multi-step pathway from arachidonic acid at which certain inhibitors act. Soybean lipoxygenase specificty and kinetics are being investigated. Interest centers around the chemical nature of the catalyzed oxygenation of linoleic acid and the manner of recognition of distances along fatty acid chains.